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Subject: Re: [PATCH V2] nvme-pci: assign separate irq vectors for adminq and
 ioq0
To:     Christoph Hellwig <hch@lst.de>,
        Jianchao Wang <jianchao.w.wang@oracle.com>
Cc:     keith.busch@intel.com, axboe@fb.com,
        linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org
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 <20180228164726.GB16536@lst.de>
From:   Sagi Grimberg <sagi@grimberg.me>
Message-ID: <ddfc2ab4-1a51-c488-25e8-bc434edf8aba@grimberg.me>
Date:   Thu, 1 Mar 2018 11:28:58 +0200
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> Note that we originally allocates irqs this way, and Keith changed
> it a while ago for good reasons.  So I'd really like to see good
> reasons for moving away from this, and some heuristics to figure
> out which way to use.  E.g. if the device supports more irqs than
> I/O queues your scheme might always be fine.

I still don't understand what this buys us in practice. Seems redundant
to allocate another vector without any (even marginal) difference.